Apparatus for removing foreign particles



Dec. 31, 1940.

F. s. SMITH 2,227,280

APPARATUS FOR REMOVING FOREIGN PARTICLES Filed sept. 1e, 1937 5 sheets-sheet 1 f 22 j 24 /7 p 1 sa ""1 `Z 32. 25 fm; l 82 55a# l /7 2 7 8O 92 2 i Il 35 l i d' G 72 36 G 82 76 /8 /5 f 5g J3 5 l '4/ 5 i 5 3 i L u d J v 26 n 5 /4 l /S 66' 8 2/ 5s( i i Q g 20 BY @faul/bl aca/ul M Y MVA-j ATTORNEYS Dec. 31, 1940.v F. s. SMITH 2,227,280

APPARATUS FOR REMOVING FOREIGN PARTICLES Filed Sept. 16, 1937 5 Sheets-Sheet 2 INVENTOR /f/zin/f/m 5MM/2.

BY @Za/LAV M,

ATTORNEY;

F. S. SM TH Dec. 3l, 1940.

APPARATUS FOR REMOVING FOREIGN PARTICLES Filed Sept. 16, 1937 3 Sheets-Sheet 3 my @AML $2/ me ATTORN EY7 Patented Dec. 31, 1940 UNITED STATES PATENT OFFICE Franklin's. smith, New Haven, conn.

Application September 16, 1937, Serial No. 164,144

1s claims. (c1. 209-224) This invention relates to the removal of particles from fiowable materials and, with regard to its more specific features, the removal of foreign objects of magnetic material from materials such as food products.

One of the objects thereof is to provide apparatus of the above nature of simple, compact, and practical construction. Another object is to provide apparatus of the above nature of efficient and dependable action. Another object is toprovide in apparatus of the above nature practical means for preventing the passage of material when the protective means are inoperative. Another object is to provide apparatus of the above nature which is readily operated and conveniently maintained in proper condition. Another object is to provide a practical and effective apparatus for the removal of materials such asforeign particles particularly from food products. Other objects will be in part obvious and in part pointed out hereinafter. Y

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts, all as will be illustratively described herein, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings in which is shown one of various possible embodiments of this invention,

Figure l is a central sectional elevation;

Figure 2 is a sectional plan taken along the line 2-2 of Figure 1;

Figure 3 is a central sectional elevation of a removable basket;

Figure 4 is an enlarged sectional view of a part of Figure l showing a section of the removal basket and associated parts; I c

Figure 5 is a sectional plan taken alongA the line 5-5 of Figure 1; and

Figure 6 is a diagrammatic illustration of the electrical connections.

Similar reference characters refer toV similar parts throughout the several views of the drawings.

Referring now to the apparatus shown in Figure 1 of the drawings, there is a supporting spider I into each of the legs of which are fitted posts II which at their lower ends t within flanged collars I2 to rest on the oor.

Supported upon this spider, as by the joint I3, is an upwardly flaring housing member I4. The upper edge of this housing has a flange I upon which rests the flange I6 of a coveror cap housing I1. These various parts are removable one and I 6 and which is threaded into the corresponding leg of the spider at 2D and held by a lock nut 2|. The upper housing I1 is provided with a central opening anged at 22, having a supply pipe 23 extending downwardly thereinto and through which is introduced the material to be treated which may consist of any product in flake,

granulated, liquid or other flowable form. A 1

downward and inward flange 24 on the upper housing I1 supports a tubular spout 26, the upper end of which is belled at 25 to rest on flange 24.

A column 21 is press-fitted in a recess in the body portion of spider I0 and extends upwardly to form the central portion of a post structure, which alines the stator 28 of an induction motor 8, as well as an iron-clad electro-magnet 9, having a winding 29. Stator 28 is rigidly clamped to a mounting sleeve 68 by a ring 6 and cap screws 5, and sleeve 68 fits about column 21 resting upon the body portion of spider II).

The outer shell 1 of electro-magnet 9 has an inner sleeve fitting about column 21 and resting upon sleeve 68. Shell 1, which provides an annular space for winding 29, includes a ringlike lower portion 10 and an outer sleeve portion 12. A frusto-conical plate 14 rests upon the top edge of sleeve portion 12 and is secured in position by suitable screws. A cap plug 16 f'lts into the upper end of sleeve 30 thus resting upon the sleeve and column 21. The shell (sleeve 30, ring-like portion 10 and sleeve portion 12) plate 14 and cap plug 16 are formed from highly magnetic material and thus provide a magnetic circuit around windng 29; there is an annular magnetic gap between the peripheral surface 18 of cap plug 16 (see also Figure 4) and the inner edge 80 of frusto-conical plate 14.

A rotatable bowl 82 formed from non-magnetic material is supported above and spaced from plate 14 and cap plug 16 in a manner to be more fully described hereinafter. An annular portion 82a of bowl 82 extends downwardly to provide a recess in the magnetic gap between cap 16 and plate 14. A non-magnetic removable basket 35, best shown in Figures 1 and 3, fits over the central portion of bowl 82 immediately above cap plug 16; basket 35 has an annular trough portion a shaped to t snugly within recess 82a of bowl 82 (Figure 4). Basket 35 is provided with a central handle 3l (Figure 3) and a central supporting lug 92 resting upon the upper surface of bowl 82 (Figure l). In this manner, basket 35 is accurately positioned and supported upon bowl 82 and rotates therewith. However, basket 35 may be easily removed through a hand hole in upper housing il provided with a cover plate 38. To permit removal of basket 35, tubular spout 26 may be lifted and canted to rest upon flange 24.

Bowl 82 4is supported upon the upper flanged edge '35 of a main casing shell 53 surrounding the electro-magnet structure. Shell 33 is supported in rotating position by a ball bearing unit 3l, whose inner race is clamped against portion 18 of shell 'l by a bracket ring 85 secured thereto by cap screws 84.

Adjacent ball bearing unit 3l (Figure 1) suitable inlet and outlet oil ports 39 are provided in shell 33, access to which may be gained by removing a cover 45 from a hand hole in the lower housing member I4.

Carried upon the lower end of main casing shell 33 is lower casing 85 having a flange 88a extending inwardly (Figure l) beneath the stator 28 of motor 8 and mounting sleeve 68. Lower casing 58, which supports the rotor 32 of the motor, is held in place on casing 33 by suitable cap screws 88. Rotor 32 has a suitable squirrel cage winding with the usual end rings and cross bars (not shown).

One leg of spider l5, as best shown in the right hand portion of Figure 1, is cored to provide a conduit for the leads 4 of motor and winding 29. A pilot light 54 is mounted upon this leg and is connected in parallel with winding 29 to indicate energization of winding 29.

It will thus be seen that, if motor 8 is energized to rotate casing shell 33, bowl 82 and basket 35, material passing downwardly from spout 26 onto basket 35 moves outwardly due to centrifugal force. This movement takes place from the top of basket 35, over trough 35a and thence upwardly over the inclined surface of bowl 82. After leaving the bowl 82, the material passes downwardly within the casing cover Il and then through the main housing member i4 to outlet spout 59. During this entire movement, the material may be eiciently processed without danger of entering the motor or contacting roller bearing unit 5| for the rotating shell structure seals these parts from the material.

As pointed out above, shell 1, cap plug l5, column 21, and plate 14 are formed from magnetic material and with winding 29 they provide an electro-magnetic path with a gap between plate i4 and plug l5; bowl 82 and basket 35 are formed from non-magnetic material. Thus upon energization of winding 2li a magnet-ic zone is set up within and adjacent trough 35a and if a magnetic object comes within this vicinity, it is drawn into the trough and tends to cling to the inner wall of the trough adjacent surface i8 of cap plug 15. In this manner, as material passes trough 25a., magnetic objects therein are drawn downwardly against the centrifugal force and the non-magnetic material passes on free of such foreign objects. Furthermore, as the material passes over trough 25d due to centrifugal force it also rotates with the rotor in addition to moving outwardly. Accordingly, the path of movement of the material across trough 35a is spiral, and the material is subjected to the action of the magnetic gap for a greater time than would be the case if the material moved in radial directions, thus allowing ample time for removing any magnetic objects which may be present therein,

Referring to Figure 6 of the drawings, in which the electrical connections are shown, the four line conductors are indicated as a whole at 42 and extend from any suitable source of current supply, the latter being assumed in this illustrative embodiment to be of the two phase type. This set of conductors, with a set of branch conductors 43, lead respectively to multi-pole switches 44 and 45 preferably held open as by the springs diagrammatically indicated at 45 and 41. The switch 44 is closed upon the energization of coil 48 acting upon a suitable core 49 when the starting switch 5D is placed in closed condition. With the closure of this switch 44, a motor 5l is energized which drives a generator 52 the fields of which are preferably of permanent magnet type. The transmission of power to generator 52 is through a fly wheel 53 of such character as to cause it to run for a substantial length of time after the motor 5l is deenergized. The output of the generator 52 passes directly to the electro-magnet winding 29, with the pilot light 54 bridged across the magnet to show when it is in operative condition.

Also bridged across the leads from the generator 52 is a conductor 55 the circuit of which is controlled by a switch arm 55 forming a part of the switch 44. This circuit leads through a coil 51 which, by a suitable core, serves to close the switch 45 and lead current to the motor 8 of the machine.

It will thus be seen that upon hand switch 50 being closed, the motor will be started to drive the generator 52 which will immediately excite electro-magnet winding 29 and indicate the eX- citation by pilot light 54. VWhen thegenerator 52 attains a certain speed, its voltage will be sucient to energize coil 51 and thus close switch 45, thereby starting the machine motor 8. If the motor 5I be shut off, the magnetic field will be maintained for a substantial time after the stoppage of the motor 8, due to the momentum of the y wheel 53 which will keep generator 52 moving at a rate to provide suflicient voltage across electro-magnet winding 29. Likewise in starting, it is assured that the magnet will be sufficiently active before the motor 8 is started.

Accordingly, the magnetic field induced by electro-magnet 29 will be sufficient at all times to retain any magnetic particles in trough 35a as long as bowl 82 rotates, for generator 52 will continue to energize electro-magnet 29 long after motor 8 has stopped.

The action of the above-described embodiment will be clear from the following:

When the raw material passes into the basket 35 and bowl 82 from the spout 26 and is rapidly rotated by these parts, it tends to travel outwardly by centrifugal force over the outer edge of the bowl and thence downwardly throughthe annular passage 58 to be discharged through the outlet spout 59. If the rotor of the motor, and consequently the bowl, are stationary, there will be no centrifugal force to move incoming material, so the material from spout 25 will simply fill up the bowl and clog the inlet before the bowl can overflow. While the bowl is rotating, however, the incoming material makes a quick outward passage due to its whirling action, and if for any reason the magnetic field is at that time dead, then foreign particles will pass along to the discharge. Here, however, the magnetic field is set up before the whirling action starts, and is of an essentially practical nature.

maintained for a substantial time after the motor 8 is stationary.

In the action of the machine, assuming that the magnet 9 is energized and the motor with the attached bowl 82 is rotating, the descending material strikes the top of basket 35 as it emerges from the spout 26. It is thus thrown outwardly in all directions and is discharged rapidly from the machine at the outlet.5;9 as hereinbefore described. The action is so rapid that the capacity of the machine is high, thus permitting a machine of small dimensions to be employed for even a large output. Furthermore, the parts are so compactly and effectively disposed `that a small fioor space is occupied. l

As the following material descends to the whirling receiving elements, any magnetic particles are snapped down into trough 35a of basket 35 by the magnetic field and are easily retained in the basket against any outward tendency due to centrifugal force. The basket may be cleaned and its metallic contents removed, as often as necessary, and the entire machine is of waterproof construction so as to facilitate cleaning.

The magnetic flux is so handled as to accentuate the dependability of its action, this flux being concentrated in the zones at which it is most useful and the foodstuff or other material which is passed through the machine suffers neither loss nor contamination in its passage.

It will thus be seen that there is provided apparatus in which the several features of this inventionare achieved and that all features thereof are The forming of the receiving hopper and basket of non-magnetic material avoids shunting of the magnetic flux.

As various changes might be made in the abovedescribed embodiment of the mechanical features of this invention, and as the art herein described might be varied, all without departing from the scope of the invention, it is to be understood that the description herein as well as the accompanying drawings are to be construed as illustrative and not in a limiting sense. l

I claim:

1. In separating apparatus, in combination, a casing, a stationary support within said casing, a plurality of magnet members disposed on said support and having annular surfaces, a shell-like non-magnetic member having a portion concentric with said annular surfaces and a cylindrical portion extending along the sides of said magnet 5,5. members, a bearing structure associated with said support and connected to the cylindrical portion of said shell-like member to provide a rotatable support therefor, an electric motor mounted upon said support and having its rotor connected to said shell-like member, and means forming an inlet immediately above the central portion of said shell-like member.

2. In separating apparatus, in combination, a casing, a stationary support within said casing, a plurality of magnet members disposed on said support and having annular surfaces, a shell-like non-magnetic member having a portion concentric with said annular surfaces and a cylindrical portion extending along the sides of said magnet members, a bearing structure associated with said support and connected to the cylindrical portion of said shell-like member to provide a rotatable support therefor, an electric motor mounted upon said support and having its rotor connected to said shell-like member, means forming an inlet immediately above the central portion of said shell-like member, the periphery of said shell-like member being spaced from the inner surface of said casing, and means forming an outlet near the base of said casing.

3. In separating apparatus, in combination, means forming a magnetic surface substantially inthe shape of an annular groove and including a bearing unit supported by said post structure and in turn supporting said rotatable member, and an electric motor having its stator mounted upon said post structure and its rotor mounted on said rotatable member.

5. In separating apparatus, in combination, means including a motor adapted to rotate the material as it is being acted upon, means forming a magnetic field adjacent said first-mentioned means, a source of current for said motor and for said field-forming means, said source of current supply including a generator, a second motor adapted to drive said generator, means supplying current to said first motor when the voltage of i said generator is above a certain value, and means supplying current from said generator to said field-forming means at all voltages of the generator.

6; In separating apparatus, in combination,

means including a motor adapted to rotate the material as it is being acted upon, means forming a magnetic field adjacent said first-mentioned means, a source of current for said motor and for said field-forming means, said source of current supply including a generator, `a second motor adapted to drive said generator, means supplying current to said rst motor when the voltage of said generator is above a certain value, and means supplying current from said generator to said fieldforming means at all voltages ofthe generator,V

and means adapted by its momentum to tend to maintain the operation of said generator after current is cut off from the driving motor.

7. In apparatus for removing foreign particles from non-magnetic materials, in combination, means forming a magnetic field, means adjacent said field adapted tol impart a rotary motion to material fed thereto, said means including an electric motor, means adapted to feed said material into said field and remove the non-magnetic material by centrifugal force due to rotary motion, means forming circuits including a source of current for said field and said motor, and electrically operated means associated with one of said circuits to delay energization of said motor circuit until said eld is formed. l

8. In apparatus for removing foreign particles from non-magnetic material, in combination, means to deliver the material to the point where it is acted upon, material moving means effective when actuated to move the material to a material outlet and effective when not actuated to prevent the movement of the material, a motor to actuate said material moving means, means including a solenoid for forming a magnetic field adjacent said alt connecting. said motor` and said motor-generator unit to a suitable source of power supply, and

' means adapted by its momentum to maintain said motor-generator unitoperating after said source of power supply has been disconnected-whereby current is supplied to maintain said magnetic field during the period that said material moving means is stopping the movement of the material.

9. In apparatus for removing foreign particles from non-magnetic material, in combination, means to deliver the material to the point where it is acted upon, material moving means effective when actuated to move the material to a material outlet and effective when not actuated to prevent the movement of the material, a motor to actuate said material moving means, means including a solenoid for forming a magnetic eld adjacent said rst-mentioned means, a motor-generator unit supplying current to said solenoid, and means connecting said motor and said motor-generator unit to a suitable source of power supply including a solenoid unit energized by current from said motor-generator unit to connect said motor to said power supply.

10. In apparatus for removing foreign particles from non-magnetic material, in combination: a mechanical separator unit comprising, actuating means to move the material from the unit, and means forming a magnetic ield to retain magnetic material within a Zone; means to deliver material to said zone and to receive material from said actuating means; and a power supply for said unit including, means to energizeV said magnetic field, means to supply mechanical power to said actuating means, and means storing a predetermined quantity of energy during operation which energy is later delivered in the form of electrical power to maintain energization of said magnetic field after power is no longer delivered to the system.

11. In separatingfapparatus, in combination, a separating plate having a central material receiving portion surrounded by an annular recess and an extended side wall construction diverging upwardly from the outer edge of said recess, means mounting said plate to rotate about a substantially vertical axis, means maintaining magnetic flux in a concentrated annular zone at said recess and surrounding -said central portion, and means to deliver material onto said central portion- Whereby the material tends to move through said zone due to centrifugal force and tends to move from said plate over said side wall construction, but magnetic material is held at said zone.

12. In separating apparatus, in combination, a

yseparating plate having a central material receiving portion and a side wall construction diverging upwardly from the outer edge of said center portion, a removable tray covering said central portion, means mounting said plate t0 rotate about a substantially vertical axis, means maintaining magnetic flux ina concentrated annular zone over said trayA surrounding said central portion, and means to deliver material onto said traywhereby the material tends to move through said zone due to centrifugal force and tends to move vfrom said plate over-said side wall construction,-

but magnetic material is held on said tray.

13. In separating apparatus, in combination, a dish member of non-magnetic material having a substantially hat centralportion and a diverging sidewalha removable tray positioned in the center of said dish member, means forming a magnetic field around the edge of said tray to maintain magnetic material on said tray, and a conduit having a telescoping end positioned over said tray to deliver material thereto.

14. In separating apparatus, in combination, a dish member of non-magnetic material having a substantially flat central portion and a diverging side wall, a removable tray positioned in the center of said dish member, means forming a magnetic eld around the edge of said tray to maintain magnetic material on said tray, and a conduit having a telescoping end positioned over said traywto deliver material thereto, said telescoping end comprising, a rigid conduit member having an inwardly extending lower flange-portion, and a slidable conduit member having an outwardly extending portion at its upper end which normally rests upon said flange portion.

l5. In a magnetic separator, the combination of: a central pole; an outer pole about said central pole; means associated with said poles to form a circumscribing zone of maximum magnetic uX concentration about said central pole; a rotatable plate structure having upwardly diverging sides and mounted concentrically with respect to said pole; said plate structure including means forming an open-topped circumscribing recess around said centrol pole at said zone of maximum magnetic flux concentration; and means to deliver material to the center of said plate structure so that the material tends to rotate with said plate structure and thereby tends to move outwardly over said recess-whereby the non-.magnetic material is thrown outwardly over said diverging sides and the magnetic material is drawn into said recess.

16. In a magnetic separator, the combination of: a concentric pole magnet having an annular gap between the poles; a rotatably mounted dish structure including a central basket with a recess extending into said gap, said dish structure having upwardly diverging side walls; motive means to transmit rotary movement to said dish structure; and means to feed material onto the center of said dish structure where the material takes of the rotation of said dish structure so that it-is'thrown along the top of said recesswhereby the non` magneticV material moves upwardly over said diverging side walls and the magnetic material is drawn into said recess.

17. In apparatus of the class described, the combination of: a funnel-shaped casing construction having a centrally positioned inlet opening at its top and a productoutlet opening at its bottom; a central rigid structure mounted within said casing and extending from its point of support near the bottom of said casing upwardly within said casing; a rotatable shell structure mounted upon and enveloping the upwardly extending end of said rigid support, the upper end of said rotatable shell structure having a central top portion positioned directly below said inlet opening at the top of said casing construction, and the outer surface of said rotatable shell structure cooperating with the inner surface of said casing construction to form a passageway down to said outlet opening; an electrical motorhaving its stator rigidly mounted upon said central rigid structure and having its rotor rigidly mounted upon said rotatable shell structure, said motor being enclosed within said rotatable shell structure and being adapted to rotate therewith; and a removable material-handling member securely supported upon said central top portion of said rotatable shell structure and having a central upwardly extending hub to defleet the product and foreign materials radially upon entering said casing construction through said inlet opening, said removable member having an annular portion where foreign materials are retained while the product due to rotation is moved beyond the top of said rotatable shell structure and is permitted to fall through said passageway between the outer wall of said rotatable shell and the inner wall of said casing construction to said outlet opening.

18. In apparatus of the class described, the combination of: a funnel-shaped casing construction having a centrally positioned inlet opening at its top and a product outlet opening at its bottom; a central rigid structure comprising a bottom spider construction formed by a plurality of axially and downwardly extending supporting legs and a central upwardly extending body portion, said central rigid structure being mounted within said casing upon said supporting' legs with its body portion extending from its point of support near the bottom of said casing upwardly within said casing; a rotatable' shell structure mounted upon and enveloping the' upwardly extending body portion of said rigid support, the upper end of said rotatable shell structure having a central top portion positioned directly below said inlet opening at the top of said casing construction, and the outer surface of said rotatable shell structure cooperating with the inner surface of said casing construction to form a pasageway down to said outlet opening; an electrical motor having its stator rigidly mounted upon said body portion of said central rigid structure and having its rotor rigidly mounted upon said rotatable shell structure, said motor being enclosed within said rotatable shell structure and being adapted to rotate therewith; and a removable material-handling member securely supported upon said central top portion of said rotatable shell structure and having a central upwardly extending hub to deect the product and foreign materials radially upon entering said casing construction through said inlet opening, said removable member having an annular portion where foreign materials are retained while the product due to rotation is moved beyond the top of said rotatable shell structure and is permitted to fall through said passageway between theouter wall of said rotatable shell and the inner Wall of said casing construction toA said outlet opening.

FRANKLIN S. SMITH. 

